The use of plastics and rubbers are widespread in today's world. The production of these plastics and rubbers are from the polymerization of monomers which are generally produced from petroleum. The monomers are generated by the breakdown of larger molecules to smaller molecules which can be modified. The monomers are then reacted to generate larger molecules comprising chains of the monomers. An important example of these monomers is light olefins, including ethylene and propylene, which represent a large portion of the worldwide demand in the petrochemical industry. Light olefins, and other monomers, are used in the production of numerous chemical products via polymerization, oligomerization, alkylation and other well-known chemical reactions. These monomers are essential building blocks for the modern petrochemical and chemical industries.
Light olefins can be generated through the conversion of oxygenates to olefins. A common process is the methanol to olefins (MTO) conversion process. The process involves many steps and includes recycling of streams such as water generated by the MTO process. However, the MTO conversion process generates solid materials and heavy hydrocarbons that can present fouling issues in the process units. Specifically, in the MTO process, unacceptable levels of contaminants, or heavy components, if not removed, can be carried over to the oxygenate stripper. The subsequent fouling of heat exchangers and downstream devices increased costs, through subsequent energy losses, and need for increased downtime to refurbish fouled devices, in particular heat exchangers. The fouling issues have been found to be the buildup of heavy hydrocarbons including highly substituted aromatics, such as hexamethyl benzene (HMB) and pentamethyl benzene (PMB).
U.S. Pat. No. 9,452,957, the entirety of which is incorporated herein by reference, discloses a process which separates heavy hydrocarbons in an MTO conversion process. While presumably effective for its intended purpose, there is a continual desire for efficient and effective processes for separating heavy hydrocarbons from an MTO reactor effluent.